A three-dimensional zincophilic layer for dendrite-free zinc metal anodes

Aqueous zinc ion battery is a promising next-generation energy storage device with high safety, low cost and environmental friendliness. However, the dendrite growth caused by uneven deposition of zinc ions and the corrosion of electrolyte on the electrode seriously shorten the cycle life of Zn anode. In this work, a three-dimensional zincophilic layer modified Zn anode (PZ-8@Zn) was prepared by electrospinning method to compound the zeolitic imidazolate framework-8 (ZIF-8) in polyacrylonitrile fiber. The coating of three-dimensional fiber layer enhances the corrosion resistance of the electrode and reduces the local current density, thus inhibiting the generation of Zn dendrites. The zincophilic ZIF-8 is beneficial to accelerate the zinc ion deposition kinetics on the electrode surface and reduce the nucleation barrier of Zn. Therefore, the PZ-8@Zn||PZ-8@Zn symmetric cells exhibits satisfactory rate performance and cycle stability, with a low overpotential of 69 mV after cycling at 3 mA cm−2 for 800 h. The PZ-8@Zn||AC capacitor has a large specific capacity of 86.1 mAh g−1 after 1000 cycles at 1 A g−1. This work provides a method to construct zinc ion deposition channels to obtain dendrite-free zinc anodes.